Organic light-emitting display device

ABSTRACT

A scanning line, signal line, first current supply line, and second current supply line are formed on a glass substrate. A first electrode is formed thereon; and, an organic layer, including a hole transport layer, light-emitting layer, electron transport layer, and electron injection layer is formed on the first electrode. A second electrode is formed as a cathode on the electron injection layer. The first electrode, serving as an anode, is connected to a plus terminal of a power source through driving devices and first current supply line, whereas the second electrode is connected to a minus terminal of the power source and is connected to the second current supply line in the display region of each pixel, with a contact hole serving as a feeding point, whereby the wiring resistance of the second electrode is reduced, and variations in the brightness of the panel is reduced.

BACKGROUND OF THE INVENTION

The present invention relates in general to an organic light-emittingdisplay device; and, more particularly, the invention relates to adisplay device that is preferable for use in displaying pictures bymeans of organic light-emitting devices.

Planar type display devices of the type used as man-machine interfaceshave received increased attention with the advent of the realmulti-media age. Such planar type display devices have used liquidcrystal displays; however, liquid crystal display devices have problemsin that they have a narrow angle of visibility and low-speed responsecharacteristics.

In recent years, organic light-emitting display devices have beenproposed as the next-generation planar type display device. In thisregard, organic light-emitting display devices have such characteristicsas excellent auto-light-emission, a wide angle of visibility, and ahigh-speed response.

In such organic light-emitting display devices, pixels are formed byorganic light-emitting elements, and the organic light-emitting displaydevice has a structure in which a first electrode, such as ITO, anorganic layer comprised of a hole transport layer, a light-emittinglayer, an electron transport layer, etc., and a second electrode havinga small work function, are provided on a glass substrate.

When a voltage of several volts is applied between the electrodes, holesare injected into the first electrode, whereas electrons are injectedinto the second electrode, and the holes and electrons pass,respectively, through the hole transport layer or the electron transportlayer so as to be coupled with each other in the light-emitting layer,whereby excitons are generated. Light is emitted when the excitonreturns to its ground state. The light thus emitted is transmittedthrough the first electrode, which is being transparent, and is takenout from the back side of the substrate.

The types of display systems using organic light-emitting elements forpixels include simple matrix organic light-emitting display devices andactive matrix organic light-emitting display devices.

The simple matrix organic light-emitting display device comprises anorganic layer comprised of a hole transport layer, a light-emittinglayer, an electron transport layer, etc. provided at positions ofintersection of pluralities of anode lines and cathode lines, and eachpixel is turned ON for a selected time during one frame period. Theselected time is a time width obtained by dividing one frame period bythe number of the anode lines. The simple matrix organic light-emittingdisplay device has the advantage of having a simple structure.

However, the selected time is shortened as the number of the pixelsincreases, so that it is necessary to raise the driving voltage tothereby enhance the instantaneous luminance during the selected time andto bring the average luminance during one frame period to apredetermined value. Thus, there is the problem that the life of theorganic light-emitting devices is shortened. In addition, since theorganic light-emitting devices are driven by an electric current, thevoltage drop due to the wiring resistance is generated, and the voltagecannot be uniformly impressed on each of the pixels, particularly in thecase of a large screen, with the result that variations in brightnessare produced in the display device. Thus, the simple matrix organiclight-emitting display device has limitations as to enhancement of thedefinition and enlargement of the screen.

On the other hand, in the active matrix organic light-emitting displaydevice, a driving device made up of a switching device composed of twoto four thin film transistors and a capacitance is connected to anorganic EL (light-emitting) device constituting each pixel, and so fullturning-ON during one frame period is possible. Therefore, it isunnecessary to enhance the brightness, and it is possible to prolong thelife of the organic light-emitting devices. Accordingly, the activematrix organic light-emitting display device is advantageous from theviewpoint of enhancement of the definition and enlargement of thescreen.

In the conventional organic light-emitting display devices, the lightbeing emitted is taken out from the back side of the substrate, andtherefore, an aperture ratio is limited in the active matrix organiclight-emitting display device in which a driving portion is providedbetween the substrate and the organic light-emitting device.

In order to solve the above-mentioned problems, attempts are provided tomake the upper second electrode transparent and to take out the emittedlight from the upper electrode side.

For example, U.S. Pat. No. 5,703,436 discloses an organic EL device inwhich the upper electrode is constituted of two layers, in which aninjection layer of Mg, Ag, etc. is used as a first layer, a transparentelectrode of ITO (Indium Tin Oxide), etc. is used as a second layer, andlight is taken out from the upper electrode.

In addition, Japanese Patent Laid-open No 6-163158 (1994) discloses anorganic EL device comprising an electron injection layer composed of atransparent alkaline earth metal oxide and a transparent cathodematerial.

Besides, Japanese Patent Laid-open No. 2001-148291 discloses a pixelstructure in which a partition wall is formed at an upper portion at theposition where an electrode of a driving device and a lower electrode ofan organic light-emitting device constituting a pixel are connected inan active matrix organic light-emitting display device. It is alsodisclosed that this structure is applicable also to a display device inwhich light is taken out from the upper electrode side.

In the device mentioned above, a transparent conductive film is used asthe second electrode to take out light from the upper electrode side. Inthis case, film formation at a low temperature is indispensable in ordernot to cause damage to the organic layer functioning as an underlyinglayer. As a result, the resistance of the film is as high as not lessthan 300 times in resistivity as compared with a metallic film of Al orthe like. In addition, even in the case where the second electrode isconstituted of a metallic film, in order to reduce the damage to theorganic layer functioning as the underlying layer, it is impossible toenlarge the thickness of the metallic film. Therefore, enlargement ofthe size of the panel poses a problem with the high resistance of theelectrode.

Besides, in the conventional active matrix organic light-emittingdisplay device, current supply lines for connecting the first electrode(anode) and the second electrode (cathode) on the opposite sides of theorganic layer of the organic light-emitting device with a power sourceare formed by use of a metallic film of a driving layer. In this case,the connection between the current supply line connected to a minusterminal of the power source and the second electrode (cathode) of theorganic light-emitting device is established through a contact holeformed in an inter-layer insulation film provided in a region free ofpixels, for example, in the vicinity of a panel edge.

In other words, the second electrode of the organic light-emittingdevice belonging to each pixel and the current supply line are connectedto each other through the contact hole. In this case, since the contacthole serves as a feeding point and the feeding point and the secondelectrode of each organic light-emitting device are connected by thecurrent supply line, the resistance of wiring the varies with thedistance from the contact hole to the pixel. Therefore, the effectivevoltage applied to the organic light-emitting device constituting thepixel varies with the wiring resistance, and the luminance value variesaccording to the position of the pixel.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide anorganic light-emitting display device in which variations in brightnessdue to the resistance of wiring connected to an electrode of an organiclight-emitting device can be reduced, as well as a method ofmanufacturing the organic light-emitting display device.

It is another object of the present invention to provide an organiclight-emitting display device in which the deterioration of imagequality due to the resistance of the wiring can be reduced, as well as amethod of manufacturing the organic light-emitting display device.

In accordance with one aspect of the present invention, there isprovided an organic light-emitting display device comprising a pluralityof pixels, each of which is a minimum unit of a picture, and a pluralityof organic light-emitting devices respectively serving as each pixel,wherein at least an electrode on one side of one organic light-emittingdevice belonging to each pixel, of a pair of electrodes disposed on theopposite sides of an organic layer of the plurality of organiclight-emitting devices, is connected to a current supply line in adisplay region of each pixel.

In constructing the organic light-emitting display device, an electrodeon one side of the pair of electrodes disposed on the opposite sides ofthe organic layer of the plurality of organic light-emitting devices maybe connected to the current supply line in the display region of eachpixel, and a color picture may be formed by use of light-emittingdevices which emit different colors as the plurality of light-emittingdevices.

In addition, in the case of forming a color image by use of a pluralityof organic light-emitting devices which emit different colors, anelectrode on one side of the organic light-emitting device of aspecified emitted color of each pixel, of the pair of electrodesdisposed on the opposite sides of the organic layer of the plurality oforganic light-emitting devices, may be connected to the current supplyline in the display region of each pixel.

Furthermore, at least one current supply line may be provided in adisplay region containing each pixel, and at least an electrode on oneside of one organic light-emitting device belonging to each pixel, ofthe pair of electrodes disposed on the opposite sides of the organiclayer of the plurality of organic light-emitting devices, may beconnected to the current supply line in the display region of eachpixel.

In constructing each of the organic light-emitting display devices asmentioned above, the following features (1) to (11) may be added.

(1) A driving layer comprising driving devices for driving the organiclayer is stacked on a substrate, a wiring layer comprising signal linesand scanning lines connected to the driving devices is stacked, theorganic layer of the plurality of organic light-emitting devices isstacked on the wiring layer on a pixel basis together with the pair ofelectrodes disposed on the opposite sides of the organic layer, and thecurrent supply line is disposed in the wiring layer and connected to theelectrode on one side through an inter-layer insulation film.

(2) A driving layer, including driving devices for driving the organiclayer, is stacked on a substrate, a wiring layer comprising signal linesand scanning lines connected to the driving devices is stacked, theorganic layer of the plurality of organic light-emitting devices isstacked on the wiring layer on a pixel basis together with the pair ofelectrodes disposed on the opposite sides of the organic layer, and thecurrent supply line is disposed between the wiring layer and the organiclayer and is connected to the electrode on one side through aninterlayer insulation film.

(3) The electrode on one side, of the pair of electrodes disposed on theopposite sides of the organic layer of the plurality of organiclight-emitting devices, is formed at an upper portion of the organiclayer on the substrate as second electrodes, relative to a firstelectrode formed at a lower portion of the organic layer on thesubstrate, and the current supply line are connected to an upper portionof the second electrode.

(4) A driving layer, including driving devices for driving the organiclayer, is stacked on a substrate, a wiring layer comprising signal linesand scanning lines connected to the driving devices is stacked, theorganic layer of the plurality of organic light-emitting devices islaminated on the wiring layer on a pixel basis together with the pair ofelectrodes disposed on the opposite sides of the organic layer, theelectrode on one side of the pair of electrodes disposed on the oppositesides of the organic layer of the plurality of organic light-emittingdevices are formed at an upper portion of the organic layer on thesubstrate as a second electrode, against a first electrode formed at alower portion of the organic layer on the substrate, and the currentsupply line is formed at an upper portion of the second electrode.

(5) The current supply line is formed as a mesh along each pixel.

(6) The current supply line is divided into a plurality of currentsupply lines in correspondence with each organic light-emitting deviceof each pixel, and the plurality of current supply lines thus dividedare connected to each organic light-emitting device of each pixel asexclusive-use current supply lines, respectively.

(7) The current supply line is formed along each space between thepixels.

(8) The current supply line is formed to overlap each pixel.

(9) The organic light-emitting devices of a specified emitted color arecomposed of a material having a higher efficiency or a longer life ascompared with the materials for the organic light-emitting devices ofother emitted colors.

(10) The electrode on one side, of the pair of electrodes disposed onthe opposite sides of the organic layer of the plurality of organiclight-emitting devices, is formed at an upper portion of the organiclayer on a substrate as a second electrode, relative to a firstelectrode formed at a lower portion of the organic layer on thesubstrate, the first electrode is connected to a plus terminal of apower source to serve as an anode, and the second electrode is connectedto a minus terminal of the power source to serve as a cathode.

(11) The second electrodes are composed of a transparent material whichtransmits light therethrough.

In accordance with another aspect of the present invention, there isprovided a method of manufacturing an organic light-emitting displaydevice, particularly for manufacturing one of the above-mentionedorganic light-emitting display devices, which comprises the steps of:forming an organic layer comprising a plurality of organiclight-emitting devices on a substrate, forming a driving layercomprising driving devices for driving the plurality of organiclight-emitting devices, forming a wiring layer comprising signal linesand scanning lines connected to the driving devices, forming currentsupply lines on the upper side of the organic layer or on the lower sideof the organic layer, forming contact holes in an interlayer insulationfilm provided in the surroundings of the current supply lines, andconnecting the electrodes on one side of pairs of electrodes disposed onthe opposite sides of the organic layer of the plurality of organiclight-emitting devices and the current supply lines through the contactholes.

According to the above-mentioned means, at least the electrode on oneside of one organic light-emitting device belonging to each pixel isconnected to the current supply line in a display region of each pixel,so that the wiring resistance of the current supply lines for connectingthe electrodes on one side of the organic light-emitting devices and apower source is uniform for each pixel, and the wiring resistance ineach pixel is negligibly small; therefore, variations in brightness dueto the resistance of the wiring for connecting the electrodes of theorganic light-emitting devices and the power source can be reduced, andvariations in the brightness in the display region can be suppressed.

Here, a pixel is the minimum unit, a plurality of which are disposed ina matrix form on a screen of a display device for displaying charactersor graphics. In addition, a sub-pixel is the minimum unit into which thepixel is further divided, in the display device for performing a colordisplay. A structure in which a color picture is composed of sub-pixelsof three colors, namely, green, red and blue sub-pixels, is generallyused. Besides, a display region is the region in which a picture isdisplayed, in a display device.

Here, an organic light-emitting device is a device having a structure inwhich a first electrode, a first injection layer, a first transportlayer, a light-emitting layer, a second transport layer, a secondinjection layer, a second electrode, and a protective film or a sealing(opposed) substrate are provided on a substrate.

The organic light-emitting device takes either of the following twoconstitutions.

The first constitution is one in which the first electrode is an anodeand the second electrode is a cathode. In this case, the first injectionlayer and the first transport layer are a hole injection layer and ahole transport layer, respectively. In addition, the second transportlayer and the second injection layer are an electron transport layer andan electron injection layer, respectively.

The second constitution is one in which the first electrode is a cathodeand the second electrode is an anode. In this case, the first injectionlayer and the first transport layer are an electron injection layer andan electron transport layer, respectively. In addition, the secondtransport layer and the second injection layer are a hole transportlayer and a hole injection layer, respectively.

In the above constitutions, it is possible to provide a structure whichlacks the first injection layer or the second injection layer. Besides,there may be a structure in which the light-emitting layer serves alsoas the first transport layer or the second transport layer.

Herein, the anode is desirably a conductive film which has a large workfunction and enhances the injection efficiency of holes. Concreteexamples include gold and platinum, but these materials are notlimitative.

Besides, the anode may be based on a binary system material, such asindium tin oxide (ITO), indium zinc oxide (IZO), indium germanium oxide,etc., or a ternary system material, such as indium tin zinc oxide, etc.Not only the compositions containing indium oxide as a main constituent,but also compositions containing tin oxide, zinc oxide or the like as amain constituent may be used. In the case of ITO, compositionscontaining 5 to 10 wt % of tin oxide in indium oxide are often used.Examples of the method of producing the oxide semiconductor include asputtering method, an EB vapor deposition method, and an ion platingmethod.

The work functions of an In₂O₃—SnO₂ based transparent conductive filmand an In₂O₃—ZnO based transparent conductive film are both 4.6 eV,which can be enhanced to about 5.2 eV by UV ozone irradiation, oxygenplasma treatment or the like.

When the In₂O₃—SnO₂ based transparent conductive film is formed bysputtering under the condition where the substrate temperature iselevated to about 200° C., the conductive film is obtained in apolycrystalline state. Since the polycrystalline state leads to a badsurface planarity due to the crystal grains, the surface is desirablypolished. As another method, formation of the transparent conductivefilm in an amorphous state and then bringing it into a polycrystallinestate by heating is desirably adopted.

With the hole injection layer provided, the anode need not be formed byuse of a material having a large work function, but it may be composedof an ordinary conductive film.

Desirable specific examples of the material of the conductive filminclude metals, such as aluminum, indium, molybdenum, and nickel, alloysof these metals, and inorganic materials, such as polysilicon, amorphoussilicon, tin oxide, indium oxide, and indium tin oxide (ITO).

In addition, organic materials, such as polyaniline, and polythiophene,and conductive inks, used with a simple coating method as the formationprocess of the conductive film may desirably be adopted. These materialsare not limitative, and these materials may be used in combination oftwo or more thereof.

The hole injection layer herein is desirably composed of a materialhaving an appropriate ionization potential in order to lower theinjection barrier between the anode and the hole transport layer.Besides, the hole injection layer desirably plays the role of buryingthe surface roughness of the underlying layer. Concrete examples of thematerial of the hole injection layer include copper phthalocyanine,starburstoamine compounds, polyaniline, polythiophene, vanadium oxide,molybdenum oxide, ruthenium oxide, and aluminum oxide, which are notlimitative.

The hole transport layer herein plays the role of transporting holes andinjecting the holes into the light-emitting layer. Therefore, the holetransport layer desirably has a high hole mobility. In addition, thehole injection layer is desirably stable chemically. The hole injectionlayer desirably has a small ionization potential, and a small electronaffinity. Besides, the hole transport layer desirably has a high glasstransition temperature. Desirable examples of the material of the holetransport layer includeN,N′-bis(3-methylphenyl)-N,N′-diphenyl-[1,1′-biphenyl]-4,4′-diamine(TPD), 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (α-NPD),4,4′,4″-tri(N-carbazolyl)triphenylamine (TCTA), and1,3,5-tris[N-(4-diphenylaminophenyl)phenylamino]benzene (p-DPA-TDAB).Naturally, these materials are not limitative, and these materials maybe used in a combination of two or more thereof.

The light-emitting layer herein is a layer in which the injected holesand electrons are coupled with each other, resulting in emission oflight at a wavelength intrinsic of the material. There are a case wherethe host material itself constituting the light-emitting layer emitslight and a case where a dopant material added in a trace amount to thehost material emits light. Desirable concrete examples of the hostmaterial include distyrilarylene derivatives (DPVBi), silole derivativeshaving a benzene ring in its skeleton (2PSP), oxodiazole derivativeshaving triphenylamine structures at both ends (EM2), perinonederivatives having a phenanthrene group (P1), oligothiophene derivativeshaving triphenylamine structures at both ends (BMA-3T), perylenederivatives (tBu-PTC), tris(8-quinolinol)aluminum,polyparapheylenevinylene derivatives, polythiophene derivatives,polyparaphenylene derivatives, polysilane derivatives, and polyacetylenederivatives. Naturally, these materials are not limitative, and thesematerials may be used in combination of two or more thereof.

Desirable specific examples of the dopant material include quinacridone,coumarin-6, Nile Red, rubrene,4-(dicyanomethylene)-2-methyl-6-(para-dimethylaminostyryl)-4H-pyran(DCM), and dicarbazole derivatives. Naturally, these materials are notlimitative, and these materials may be used in a combination of two ormore thereof.

The electron transport layer herein plays the role of transportingelectrons and injecting the electrons into the light-emitting layer.Therefore, the electron transport layer desirably has high electronmobility. Desirable concrete examples of the material of the electrontransport layer include tris(8-quinolinol)aluminum, oxadiazolederivatives, silole derivatives, and zinc-benzothiazole complex.Naturally, these materials are not limitative, and these materials maybe used in a combination of two or more thereof.

Examples of methods of manufacturing the hole injection layer, the holetransport layer, the light-emitting layer, and the electron transportlayer noted above include a vacuum vapor deposition method, an electronbeam (EB) vapor deposition method, a sputtering method, a spin coatingmethod, a cast method, and an ink-jet method.

It is desirable that patterning for each of the layers be performed inthe deposition method as follows: a mask provided with an opening shapedcorrespondingly to the shape of a pattern is kept in intimate contactwith or close to a substrate, and, in this state, a material isevaporated from a source of evaporation to the substrate so as to formthe pattern thereon.

It is desirable that patterning by the spin coating method and the castmethod be performed as follows: a portion other than a pattern of a thinfilm formed over the entire surface of a substrate is exfoliated bylaser ablation or the like, leaving the pattern on the substrate.

It is desirable that patterning for each of the layers be performed inan ink-jet method as follows: a soluble organic material is dissolved ina solvent, and the resulting solution is ejected from a movable nozzleonto a substrate so as to form the shape of a pattern thereon.

The electron injection layer herein is used for enhancing the efficiencyof electron injection from the cathode into the electron transportlayer. Desirable specific examples of the material of the electroninjection layer include lithium fluoride, magnesium fluoride, calciumfluoride, strontium fluoride, barium fluoride, magnesium oxide, andaluminum oxide. Naturally, these materials are not limitative, and thesematerials may be used in a combination of two or more thereof.

The cathode herein is desirably a conductive film which has a small workfunction and enhances the injection efficiency of electrons. Specificexamples of the material of the cathode include a magnesium-silveralloy, aluminum-lithium alloy, aluminum-calcium alloy,aluminum-magnesium alloy, and metallic calcium, which are notlimitative.

With provision of the above-mentioned electron injection layer, thecathode need not be formed by use of a material having a low workfunction, and a general metallic material can be used. Desirablespecific examples include metals, such as aluminum, indium, molybdenum,and nickel, alloys of these metals, polysilicon, and amorphous silicon.

In accordance with the present invention, when the cathode is used asthe second electrode (transparent electrode), it is desirable to providethe electron injection layer at a lower portion of the cathode. Withprovision of the electron injection layer, a transparent conductive filmhaving a high work function can be used as the cathode. Specificexamples include an In₂O₃—SnO₂ based transparent conductive film and anIn₂O₃—ZnO based transparent conductive film. In particular, theIn₂O₃—SnO₂ based transparent conductive film is used as pixel electrodesin a liquid crystal display system.

The protective layer herein is formed on the second electrode, for thepurpose of preventing H₂O and O₂ in the atmosphere from penetrating intothe second electrode or into the organic layer provided under the secondelectrode.

Specific examples of the material of the protective layer includeinorganic materials, such as SiO₂, SiNx, and Al₂O₃, and organicmaterials, such as polychloropyrene, polyethylene terephthalate,polyoxymethylene, polyvinyl chloride, polyvinilydene fluoride,cyanoethyl-pullulan, polymethyl methacrylate, polysulfone,polycarbonate, and polyimide, which are not limitative.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and advantages of the invention will become apparent fromthe following description of various embodiments with reference to theaccompanying drawings in which:

FIG. 1 is a plan view of a pixel region in an organic light-emittingdisplay device according to a first embodiment of the present invention;

FIG. 2A is a sectional view taken along line A-A′ of the pixel regionshown in FIG. 1;

FIG. 2B is a sectional view taken along line B-B′ of the pixel regionshown in FIG. 1;

FIG. 3A is a schematic diagram illustrating the relationship between asecond current supply line and a feeding point in a conventional organiclight-emitting display device;

FIG. 3B is a schematic diagram illustrating the relationship between asecond current supply line and a feeding point in an organiclight-emitting display device according to the present invention;

FIG. 4 is a plan view of a pixel region in an organic light-emittingdisplay system according to a second embodiment of the presentinvention;

FIG. 5 is a sectional view taken along line A-A′ of the pixel regionshown in FIG. 4;

FIG. 6 is a plan view of a pixel region in an organic light-emittingdisplay system according to a third embodiment of the present invention;

FIG. 7 is a sectional view taken along line A-A′ of the pixel regionshown in FIG. 6;

FIG. 8 is a plan view of a pixel region in an organic light-emittingdisplay system according to a fourth embodiment of the presentinvention;

FIG. 9 is a sectional view taken along line A-A′ of the pixel regionshown in FIG. 8;

FIG. 10 is a plan view of a pixel region in an organic light-emittingdisplay system according to a fifth embodiment of the present invention;

FIG. 11 is a sectional view taken along line A-A′ of the pixel regionshown in FIG. 10;

FIG. 12 is a plan view of a pixel region in an organic light-emittingdisplay system according to a sixth embodiment of the present invention;

FIG. 13 is a sectional view taken along line A-A′ of the pixel regionshown in FIG. 12;

FIG. 14 is a plan view of a pixel region in an organic light-emittingdisplay system according to seventh embodiment of the present invention;

FIG. 15 is a sectional view taken along line A-A′ of the pixel regionshown in FIG. 14;

FIG. 16 is a plan view of a pixel region in an organic light-emittingdisplay system according to eighth embodiment of the present invention;

FIG. 17 is a sectional view taken along line A-A′ of the pixel regionshown in FIG. 16;

FIG. 18 is a plan view of a pixel region in an organic light-emittingdisplay system according to a ninth embodiment of the present invention;

FIG. 19 is a sectional view taken along line A-A′ of the pixel regionshown in FIG. 18;

FIG. 20 is an equivalent circuit diagram of a pixel of the organiclight-emitting display system according to the first embodiment of thepresent invention;

FIG. 21 is a plan view of a pixel region in an organic light-emittingdisplay system according to a tenth embodiment of the present invention;

FIG. 22 is a sectional view taken along line A-A′ of the pixel regionshown in FIG. 21;

FIG. 23 is a plan view of a pixel region in an organic light-emittingdisplay system according to an eleventh embodiment of the presentinvention;

FIG. 24 is a sectional view taken along line A-A′ of the pixel regionshown in FIG. 23;

FIG. 25 is a plan view of a pixel region in an organic light-emittingdisplay system according to a twelfth embodiment of the presentinvention; and

FIG. 26 is a sectional view taken along line A-A′ of the pixel regionshown in FIG. 25.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[Embodiment 1]

An organic light-emitting display system according to a first embodimentof the present invention will be described below with reference to thedrawings. FIG. 1 is a plan view of a pixel in the organic light-emittingdisplay device; FIG. 2A is a sectional view taken along line A-A′ ofFIG. 1; and FIG. 2B is a sectional view taken along line B-B′ of FIG. 1.In FIGS. 1, 2A and 2B, a plurality of scanning lines 106, 106′ aredisposed at a predetermined interval on a glass substrate 116, andsignal lines 109, 109′, 109″ for transmitting picture data and the likeare disposed at a predetermined interval in a direction orthogonal toeach of the scanning lines. That is, the scanning lines and the signallines are arranged in a grid form, and the region surrounded by a pairof the scanning lines and a pair of the signal lines constitutes adisplay region for one pixel. On the glass substrate 116, a plurality offirst current supply lines 110 connected to a plus terminal of a powersource are disposed in parallel to the signal lines 109, and a pluralityof second current supply lines 111 connected to a minus terminal of thepower source are disposed in parallel to the signal lines 109 and thefirst current supply lines 110. The scanning lines 106, the signal lines109, the first current supply lines 110 and the second current supplylines 111 are provided as wiring belonging to a wiring layer on theglass substrate 116, with an inter-layer insulation film disposedtherebetween.

A plurality of organic light-emitting devices constituting a pixel thatrepresents a minimum unit of a color picture is disposed on the upperside of the wiring layer. Each of the organic light-emitting devices isprovided as a sub-pixel, which comprises an organic layer including ahole transport layer 121, a light-emitting layer 122, an electrontransport layer 123, and an electron injection layer 124, and a firstelectrode (anode) 115 and a second electrode (cathode) 125 disposed onthe opposite sides of the organic layer. The first electrode 115 of theorganic light-emitting device belonging to each pixel is connected tothe first current supply line 110 through a transistor serving as adriving device, whereas the second electrode 125 of the organiclight-emitting device belonging to each pixel is connected to the secondcurrent supply line 111 through a contact hole 114 formed in a secondinterlayer insulation film 119 and a third interlayer insulation film120 in the display region of each pixel. That is, the second electrode125 of the organic light-emitting device belonging to each pixel isconnected to the second current supply line 111, with the contact hole114 serving as a feeding point.

On the glass substrate 116, in addition, a driving layer for driving theorganic layer of each pixel is provided. The driving layer comprises afirst transistor 101, a second transistor 102 and a capacitance 104 asdriving devices. The gate of the first transistor 101 is connected tothe scanning line 106, the source is connected to the signal line 109,and the drain is connected to the gate of the second transistor and anupper electrode 108 of the capacitance 104. The drain of the secondtransistor 102 is connected to a lower electrode 105 of the capacitance104 and the first current supply line 110, and the source is connectedto the first electrode 115. FIGS. 1, 2A and 2B show only the structureof one pixel.

Next, a method of manufacturing the organic light-emitting displaysystem constituted as indicated above will be described. First, anamorphous silicon (a-Si) film of 50 nm in thickness is formed on theglass substrate 116 by a low-pressure chemical vapor deposition method(LPCVD method). The material is Si₂H₆, and the substrate temperature isset at 450° C. Next, the whole surface of the film is subjected to alaser anneal treatment by use of an XeCl excimer laser. The laser annealtreatment is conducted in two stages, and the irradiation energies atthe first time and the second time are 188 mJ/cm² and 290 mJ/cm²,respectively. With this processing, the amorphous silicon iscrystallized to become polycrystalline silicon (p-Si). Next, thepolycrystalline silicon is patterned by dry etching using CF₄, to forman active layer 103 of the first transistor 101, an active layer 103′ ofthe second transistor 102, and the lower electrode 105 of thecapacitance 104.

Next, an SiO₂ film of 100 nm in thickness is formed as a gate insulationfilm 117. The SiO₂ film was formed by a plasma-enhanced chemical vapordeposition method (PECVD method) using tetraethoxysilane (TEOS) as amaterial.

Subsequently, a TiW film of 50 nm in thickness is formed by a sputteringmethod, and this film is patterned to form gate electrodes 107, 107′. Inconjunction with this, the scanning line 106 and the upper electrode 108of the capacitance are also patterned.

Next, P ions were injected into the patterned polycrystalline siliconlayer from the upper side of the gate insulation film 117 by an ioninjection method under the conditions of 4×10¹⁵ ion/cm² and 80 keV. Atthis time, the P ions are not injected into the regions where the gateelectrodes 107, 107′ are present on the upper side, and the regionsbecome active regions 103, 103′.

Subsequently, the substrate 116 is heated in an inert N₂ gas atmosphereat 300° C. for 3 hours to activate the ions so that doping can beperformed effectively. The ion-injected region of the polycrystallinesilicon (p-Si) comes to have a sheet resistance of 2 kΩ/□. A siliconnitride (SiNx) film is formed thereon as a first interlayer insulationfilm 118 with a thickness of 200 nm.

Next, contact holes (not shown) are formed in the gate insulation film117 and the first interlayer insulation film 118 at upper portions atboth ends of the active layers 103, 103′. Further, a contact hole (notshown) is formed in the first interlayer insulation film 118 at an upperportion of the gate electrode 107′ of the second transistor 102.

On the upper side of this, an Al film of 500 nm in thickness is formedby a sputtering method. The signal line 109, the first current supplyline 110 and the second current supply line 111 are formed by aphotolithographic step. In addition, a source electrode 112 and a drainelectrode 113 of the first transistor 101, as well as a source electrode112′ and a drain electrode 113′ of the second transistor 102, areformed.

Next, the capacitance lower electrode 105 is connected to the drainelectrode 113 of the first transistor 101, and the source electrode 112of the first transistor 101 is connected to the signal line 109. Inaddition, the drain electrode 113 of the first transistor 101 isconnected to the gate electrode 107′ of the second transistor 102, andthe drain electrode 113′ of the second transistor 102 is connected tothe first current supply line 110. Further, the upper electrode 108 ofthe capacitance 104 is connected to the first current supply line 110.

Subsequently, an SiNx film is formed through the second interlayerinsulation film 119. The SiNx film has a thickness of 500 nm. A contacthole (not shown) is formed at an upper portion of the drain electrode112′ of the second transistor 102, and an ITO film of 150 nm inthickness is formed thereon by a sputtering method, and the firstelectrode 115 is formed by a photolithographic method.

Next, as a third interlayer insulation film 120, a positive typephotosensitive protective film (PC452), a product by JSR, is formed. Inthis case, the film is formed by a spin coating method under coatingconditions of 1000 rpm and 30 sec, the substrate 116 is placed on a hotplate, and prebaking is performed at 90° C. for 2 min.

Subsequently, exposure to a ghi line mixture is conducted by use of aphotomask to form contact holes 114 in a stripe pattern. Next,development is conducted by use of a developing liquid PD-523, a productby JSR, at room temperature for 40 sec, and, after the development,rinsing with pure water is carried out at room temperature for 60 sec.After the rinsing, post-exposure is conducted at a wavelength of 365 nmand an intensity of 300 mJ/cm², and post-baking is conducted in a cleanoven at 220° C. for 1 hr.

The thickness of the third interlayer insulation film 120 formed ofPC452 is 2 μm, and the edges of the first electrode 115 are covered by 6μm.

Next, the structure of the organic light-emitting device constituting apixel will be described with reference to FIG. 2B. The glass substrate116, provided with elements up to the first electrode 115, is subjectedto ultrasonic cleaning for 3 min sequentially in acetone and in purewater, followed by spin drying and drying in an oven at 120° C. for 30min.

Subsequently, O₂ plasma cleaning is conducted. The degree of vacuum inthe plasma-cleaning chamber is 3 Pa, the flow rate of O₂ is 22 ml/min,the RF power is 200 W, and the cleaning time is 3 min. After the O₂plasma cleaning, the substrate 116 is set into a vacuum vapor depositionchamber without exposure to the atmosphere.

Next, a 4,4-bis[N-(1-naphthyl)-N-phenylamino]biphenyl film (hereinafterreferred to as α-NPD film) of 50 nm in thickness is formed on the firstelectrode 115 by a vacuum vapor deposition method.

About 60 mg of the material is put in a Mo-made sublimation boat, andvapor deposition is conducted at a vapor deposition rate of 0.15±0.05nm/sec. At this time, the pattern is formed by use of a shadow mask. Thevapor deposition area is 1.2 times each side of the first electrode 115.The α-NPD film functions as a hole transport layer 121.

On the upper side of this, a co-vapor deposition film oftris(8-quinolinol)aluminum and quinacridon (hereinafter referred to asAlq and Qc, respectively) of 20 nm in thickness is formed by a binarysimultaneous vacuum vapor deposition method.

The materials Alq and Qc in amounts of about 40 mg and about 10 mg areput in two Mo-made sublimation boats, respectively, and co-vapordeposition is conducted at vapor deposition rates of 0.40±0.05 nm/secand 0.01±0.005 nm/sec, respectively. The Alq+Qc co-vapor deposition filmfunctions as the light-emitting layer 122. An Alq film of 20 nm inthickness is formed thereon by a vacuum vapor deposition method. About40 mg of the material is put in an Mo-made sublimation boat, and vapordeposition is conducted at a vapor deposition rate of 0.15±0.05 nm/sec.The Alq film functions as the electron transport layer 123.

A mixture of Mg and Ag, serving as the electron injection layer 124 isformed on the electron transport layer 123. In this case, a film of 10nm in thickness is formed by a binary simultaneous vacuum vapordeposition method at vapor deposition rates of 0.14±0.05 nm/sec and0.01±0.005 nm/sec for Mg and Ag, respectively.

Next, an In—Zn—O film (hereinafter referred to as an IZO film) of 50 nmin thickness is formed by a sputtering method. The film functions as thesecond electrode 125 and is an amorphous oxide film. A target withIn/(In+Zn)=0.83 is used. The film formation conditions include an Ar:O₂mixture gas as the atmosphere, a degree of vacuum of 0.2 Pa, and asputtering output of 2 W/cm². The second electrode 125 composed of anMg:Ag/In—Zn—O laminate film functions as a cathode, which has atransmittance of 65%. In this case, as shown in FIG. 2A, the secondelectrode 125 is connected to the second current supply line 111, withthe contact hole 114 formed in the second interlayer insulation film 119and the third interlayer insulation film 120 serving as a feeding point.That is, the second electrode 125 of the organic light-emitting deviceof each pixel is connected to the second current supply line 111 in theregion of each pixel, using the contact hole 114 as a feeding point.

Subsequently, an SiNx film of 50 nm in thickness is formed on the secondelectrode 125 by a thermal CVD method. This film functions as theprotective film 126.

In the organic light-emitting display device according to the presentembodiment, the emitted light is taken out from the side of theprotective layer 126, so that the IZO film is used as the secondelectrode 125. The IZO film has a sheet resistance of 80 Ω/□.

In the case of using the IZO film as the second electrode 125 andconnecting the second electrode 125 to the second current supply line111, when the feeding point for the second electrode 125 of each pixelis provided at an end portion of the display region of the panel, andthis feeding point is connected to the second electrode 125 of eachpixel through the second current supply line 111, as shown in FIG. 3A,differences are generated in the wiring resistance due to the IZO filmbetween the pixels disposed at the end portion of the display region ofthe panel and the pixels disposed at a central portion of the displayregion of the panel, so that variations are generated in the voltageapplied to each pixel, and thereby variations occur in the brightness ofthe panel.

On the other hand, in the organic light-emitting display deviceaccording to this embodiment, as shown in FIGS. 2A, 2B and 3B, thesecond electrode 125 of the organic light-emitting device of each pixeland the second current supply line 111 are connected to each other inthe display region of each pixel, with the contact hole 114 serving as afeeding point Therefore, the wiring resistance due to the IZO film ineach pixel becomes uniform, so that generation of the variations in thevoltage applied to each pixel can be prevented, and thereby generationof the variations in the brightness of the panel can be prevented.

In addition, the second current supply line 111 in this embodiment has atotal wiring resistance of about 0.2 Ω, so that the wiring resistance ineach pixel is negligibly small, and the generation of the variations inthe brightness of the panel can be suppressed.

[Embodiment 2]

A full color organic light-emitting display device according to a secondembodiment of the present invention will be described with reference toFIGS. 4 and 5. This display device comprises a second current supplyline and a feeding point at a lower portion of a green emission pixelregion, and it has a high efficiency and a long life. FIG. 4 is a planview of a pixel of an organic light-emitting display device according tothis embodiment, and FIG. 5 is a sectional view taken along line A-A′ ofthe pixel region shown in FIG. 4.

The present embodiment has a structure in which, to display a colorpicture, a plurality of pixels serving as minimum units of the colorpicture are provided; green, red and blue organic light-emitting devicesare provided as sub-pixels constituting each pixel; and a secondelectrode 125 of the organic light-emitting device of each pixel isconnected to a second current supply line 111 in the display region ofthe green organic light-emitting device, the other constitutions beingsubstantially the same as those in the first embodiment.

More particularly, there are formed on a glass substrate 116 a, a greenpixel first transistor 204, a green capacitance 205, a green secondtransistor 206, a red pixel first transistor 207, a red capacitance 208,a red second transistor 209, a blue pixel first transistor 210, a bluecapacitance 211, a blue second transistor 212, signal lines 109, 109′,109″, scanning lines 106, 106′, first current supply lines 110, 110′,110″, a second current supply line 111, a first interlayer insulationfilm 118, a second inter-layer insulation film 119 and a contact hole114, using the same methods as in the first embodiment

The organic light-emitting devices constituting the green pixel, redpixel and blue pixel are formed by the following method.

A green pixel first electrode 201, a red pixel first electrode 202 and ablue pixel first electrode 203 are formed on the second interlayerinsulation film 119. The method used for this is the same as that forforming the first electrode 115 in the first embodiment. The firstelectrodes 201, 202, 203 are connected respectively to source electrodesof the second transistors 206, 209, 212 through contact holes (notshown) formed in the second interlayer insulation film 119, and thegreen pixel first electrode 201 is not covered with the feeding pointconstituted of the contact hole 114.

Next, as with the first embodiment, a third interlayer insulation film120 is formed, and the third interlayer insulation film 120 is also notcovered with the feeding point constituted of the contact hole 114.

Subsequently, an α-NPD layer serving as a hole transport layer 121 incommon for each pixel is formed on the first electrodes 201, 202, 203.The formation conditions are the same as in Embodiment 1, the filmthickness is controlled to 50 nm, and the vapor deposition rate iscontrolled to 0.15±0.05 nm/sec. The vapor deposition is conducted by useof a mask so that the feeding point is not covered with the holetransport layer 121.

Next, light-emitting layers 213, 214, 215 of each pixel are formed. Aco-vapor deposition layer of Alq and Qc is formed as the light-emittinglayer 213 of the green pixel. The formation conditions are the same asin the first embodiment.

Subsequently, the light-emitting layer 214 of the red pixel is formed.That is, a co-vapor deposition film of Alq and Nile Red (hereinafterabbreviated to Nr) of 40 nm in thickness is formed by a binarysimultaneous vacuum vapor deposition method.

The materials Alq and Nr in respective amounts of about 10 mg and about5 mg are put in two Mo-made sublimation boats, and vapor deposition isconducted at vapor deposition rates of 0.40±0.05 nm/sec and 0.01±0.005nm/sec for Alq and Nr, respectively.

Next, the light-emitting layer 215 of the blue pixel is formed. That is,a distyrylarylene derivative film (hereinafter abbreviated to DPVBi) of40 nm in thickness is formed by a vacuum vapor deposition method. Thematerial DPVBi, in an amount of about 40 mg, is put in an Mo-madesublimation boat, and vapor deposition is conducted at a vapordeposition rate of 0.40±0.05 nm/sec.

Subsequently, an electron transport layer 123, common for each pixel, isformed. That is, an Alq film of 20 nm in thickness is formed by a vacuumvapor deposition method. In this case, about 40 mg of the material isput in an Mo-made sublimation boat, and vapor deposition is conducted ata vapor deposition rate of 0.15±0.05 nm/sec.

Next, an Mg—Ag alloy film serving as an electron injection layer 124 isformed on the electron transport layer 123. The formation conditions arethe same as in the first embodiment. An IZO film serving as a secondelectrode 125 is formed thereon. The formation conditions are the sameas in the first embodiment.

The second electrode 125 is connected to the second current supply line111, with the contact hole 114 formed in the second interlayerinsulation film 118 and the third interlayer insulation film 119 servingas a feeding point.

Subsequently, an SiNx film of 50 nm in thickness is formed by a thermalCVD method. This film functions as a protective layer 126.

In this embodiment, as with the first embodiment, the contact hole 114is provided for connecting the second electrode 125 and the secondcurrent supply line 111 in the display region of each pixel, so thatvariations in wiring resistance due to the second electrode 125 aresuppressed, and the variations in brightness of the panel can bereduced.

In addition, in this embodiment, the second current supply line 111 isformed in the green pixel region and is not formed in the red pixel andblue pixel regions, so that lowering of the aperture ratio due toformation of the contact hole 114 is not generated in the red pixel andblue pixel region, though a lowering of the aperture ratio is generatedin the green pixel region. In this case, if the lowering of the apertureratio in the green pixel region is 10%, it is possible to accommodatethe lowering of the aperture ratio by increasing the brightness by 10%.In other words, since the current density is proportional to thebrightness, it is possible to accommodate the lowering of the apertureratio by increasing the current density by 10%. It should be noted thateven if the current density is increased by 10%, the current flowing tothe green pixel is not varied because the aperture ratio is lowered by10%.

On the other hand, if the brightness in a non-linear relationship withthe voltage is increased by 10%, the voltage is increased by 1 to 2%.Therefore, if the brightness is increased by 10%, the increase in poweris 1 to 2%. Incidentally, the efficiency of the organic light-emittingdevice used for the green pixel is several fold greater than those ofthe materials of the red and blue devices, so that the increase in powerdoes not matter in a full-color panel.

Therefore, by adopting the structure according to this embodiment,variations in brightness in the panel can be suppressed without loweringthe efficiency of the full-color panel.

[Embodiment 3]

A full-color organic light-emitting display device according to a thirdembodiment of the present invention will be described with reference toFIGS. 6 and 7. This display device, which comprises a second currentsupply line and a feeding point at a lower portion of a green lightemission pixel region, is so constructed as to take out light from theback side of a substrate, and has a high efficiency and a long life.FIG. 6 is a plan view of a pixel of the organic light-emitting displaydevice in this embodiment, and FIG. 7 is a sectional view taken alongline A-A′ of FIG. 6.

In this embodiment, a sealing substrate 309 for the purpose ofpreventing water, oxygen and the like gases in the atmosphere frompenetrating into a second electrode 125, an organic layer under thesecond electrode, or the interface between the second electrode and theorganic layer is provided on the upper side of the second electrode 125,the other constitutions being substantially the same as in the secondembodiment.

More particularly, there are formed on a glass substrate 116, a greenpixel first transistor 204, a green capacitance 205, a green secondtransistor 206, a red pixel first transistor 207, a red capacitance 208,a red second transistor 209, a blue pixel first transistor 210, a bluecapacitance 211, a blue second transistor 212, signal lines 109, 109′,109″, scanning lines 106, 106′, first current supply lines 110, 110′,110″, a second current supply line 111, a first inter-layer insulationfilm 118, and a second inter-layer insulation film 119, using the samemethods as used in the second embodiment.

Next, first electrodes 301, 302, 303 of green, red and blue pixels areformed on the second interlayer insulation film. The formationconditions are the same as in the second embodiment. This embodimentdiffers from the second embodiment in that the green pixel firstelectrode 301 is so small that it does not overlap with the capacitance205, the first current supply line 110 or the second current supply line111.

Subsequently, as with the second embodiment, a contact hole 114 isformed in the second interlayer insulation film 119 and the thirdinterlayer insulation film 120, and the contact hole 114 is provided toserve as a feeding point.

On the upper side of this, a hole transport layer 121 is formed incommon for green, red and blue pixels. The method of formation is thesame as in the second embodiment.

Next, light-emitting layers 304, 305, 306 of each pixel are formed bythe same method as used in the second embodiment.

An electron transport layer 123 common for green, red, blue pixels isformed on the light-emitting layers 304, 305, 306 of each pixel, by thesame method as used in Embodiment 2.

Subsequently, an LiF film serving as an electron injection layer 124 isformed on the electron transport layer 123. The film of 0.5 nm inthickness was formed by a vacuum vapor deposition method at a vapordeposition rate of 0.05±0.01 nm/sec.

Next, an Al film serving as a second electrode 125 is formed on theelectron injection layer 124. The film of 150 nm in thickness is formedby a vacuum vapor deposition method at a vapor deposition rate of 1±0.05nm/sec.

The second electrode 125 is connected to the second current supply line111, with the contact hole 114 formed in the second inter-layerinsulation film 119 and the third inter-layer insulation film 120serving as a feeding point.

Subsequently, the substrate (organic EL substrate) 106 provided with thedriving portions and the organic light-emitting devices is moved into asealed chamber, in which the dew point is maintained at −90° C. whilecirculating a dried nitrogen gas, without exposing the substrate 106 tothe atmosphere.

Next, a glass substrate is introduced into the sealed chamber. The glasssubstrate becomes a sealing substrate (opposed substrate) 309. Aphoto-curable resin was applied to edge portions of the sealingsubstrate 309 constituted of the glass substrate by use of a sealdispenser device.

The sealing width of the photo-curable resin is 200 μm. Glass beads of10 μm in diameter are loaded in the photo-curable resin in an amount of1 wt %. The sealing substrate 309 and the organic EL substrate 310 areadhered to each other in the sealed chamber, and they are pressedagainst each other under a load of 0.5 kgw/cm². A light shield plate isplaced on the outside of the sealing substrate 309 so that the wholepart of the display region is shielded from UV light, and irradiationwith UV light from the side of the sealing substrate 309 is conducted tocure the photo-curable resin.

An alkali meta-halide lamp is used as a source of UV light at anirradiation intensity of 4000 mJ/cm² for an irradiation time of 4 min.

The gap length between the organic EL substrate 310 and the sealingsubstrate 309 is determined by the diameter of the glass beads containedin the photo-curable resin to be 10 μm.

In this embodiment, as with the first embodiment, a feeding point forconnecting the second electrode 125 and the second current supply line111 is provided in the inside of the pixel, so that dispersion of thewiring resistance due to the resistance of the second electrode 125 issuppressed, and variations in the brightness of the panel are reduced.

Besides, in this embodiment, as with the second embodiment, the secondcurrent supply line 111 is formed only at a lower portion of the greenpixel region, so that the current per pixel is not varied even in thecase where the aperture ratio of the green pixel is about 50%. On theother hand, the voltage is increased by about 7%. Therefore, in thisembodiment, the power is increased by about 7%, but this does not leadto a lowering of the performance of the full-color panel in the samemanner as in the second embodiment.

[Embodiment 4]

A full-color organic light-emitting display device according to a fourthembodiment of the present invention will be described with reference toFIGS. 8 and 9. This display device comprises a second current supplyline on the upper side of a second electrode. FIG. 8 is a plan view of apixel of the organic light-emitting display device according to thisembodiment, and FIG. 9 is a sectional view taken along line A-A′ of FIG.8.

In this embodiment, in place of forming a second current supply line 111in the same layer as a signal line 109, an Al film 402 serving as thesecond current supply line is formed on the upper side of a protectivelayer 126 covering a second electrode 125 of an organic light-emittingdevice belonging to each pixel, and emitted light is taken out from theback side of the substrate, the other constitutions being substantiallythe same as in the first embodiment.

More particularly, there are formed on a glass substrate 116, a firsttransistor 101, a capacitance 104, a second transistor 102, signal lines109, 109′, scanning lines 106, 106′, first current supply lines 110,110′, a second inter-layer insulation film 119, a first electrode 115,and a third inter-layer insulation film 120, using the same methods asused in the first embodiment.

On the upper side of this, a hole transport layer 121, a light-emittinglayer 122 and an electron transport layer 123 are formed by the samemethod as used in the embodiment.

Next, an LiF film serving as an electron injection layer 124 is formedon the electron transport layer 123 under the same conditions as in thethird embodiment.

Subsequently, an Al film serving as a second electrode 124 is formed onthe electron injection layer 124 under the same conditions as in thethird embodiment.

Next, an SiNx film of 100 nm in thickness is formed by a thermal CVDmethod. The film is removed, while leaving an upper portion on the pixelregion where the first electrode 115 and the second electrode 125overlap with each other, by a photolithographic method. In FIGS. 8 and9, the removed regions are regions 401 and 401′. In this case, the SiNxfilm functions as a protective layer 126 in the pixel region.

An Al film is formed on the protective layer 126 by a sputtering methodto a film thickness of 500 nm. This layer functions as a second currentsupply line. With the protective film 126 provided in the pixel region,the damage to the electron transport layer 123, the light-emitting layer122 and the hole transport layer 121 as lower layers due to theformation of the Al film is reduced.

In the organic light-emitting display system according to thisembodiment, the second current supply line 402, that is formed at anupper portion of the second electrode 125 of each pixel, is connected tothe second electrode 125 through the contact hole (not shown) formed inthe protective layer 126 and the regions 401, 401′ in the vicinity ofeach pixel, so that variations in the wiring resistance of the secondelectrode 125 are reduced, and, as a result, variations in thebrightness of the panel surface can be reduced.

In addition, since the second current supply line 402 formed on theprotective layer 126 has a protective function, the life of the organiclight-emitting display device can be prolonged.

[Embodiment 5]

An organic light-emitting display device according to a fifth embodimentof the present invention will be described with reference to FIGS. 10and 11. This display device comprises second current supply lines in amesh form (grid form). FIG. 10 is a plan view of a pixel of the organiclight-emitting display device according to this embodiment, and FIG. 11is a sectional view taken along line A-A′ of FIG. 10.

In this embodiment, in forming the second current supply lines in a meshform, the second current supply lines 501, 501′ are formed in parallelto signal lines 109, 109′, and the second current supply line 502 isformed in parallel to scanning lines 106, 106′, so that the area of thesecond current supply lines as a whole is increased, whereby a loweringin the resistance of the second current supply lines is achieved, theother constitutions being substantially the same as in the first andsecond embodiments.

More particularly, an active layer 103 of a first transistor 101, anactive layer 103′ of a second transistor 102, and a lower electrode 105of a capacitance are formed on a glass substrate 116 by the same methodsas in the first embodiment.

Next, a gate insulation film 117 is formed by the same method as used inthe first embodiment. On the upper side of this, a gate electrode 107,the scanning lines 106, 106′, and an upper electrode 108 of thecapacitance are formed by patterning. In this layer, the second currentsupply line 502 is formed.

On the upper side of this, a first inter-layer insulation layer 118 isformed under the same conditions as in the first embodiment.

Next, contact holes are formed in the gate insulation film 117 and thefirst interlayer insulation layer 118 at upper portions of both ends ofthe active layers 103, 103′. Further, a contact hole is formed in thefirst interlayer insulation layer 127 at an upper portion of the gateelectrode 121 of the second transistor 102. Furthermore, a contact hole504′ is formed on the second current supply line 502.

On the upper side of this, a signal line 109, a first current supplyline 110 and the second current supply lines 501, 501′ are formed in thesame manner as in the first embodiment. The second current supply line502 is connected to the second current supply line 501′ at a feedingpoint 504′.

In addition, a source electrode 112 and a drain electrode 113 of thefirst transistor 101, as well as a source electrode 112′ and a drainelectrode 113′ of the second transistor 102, are formed.

The capacitance lower electrode 105 is connected to the drain electrode113 of the first transistor 101, the source electrode 112 of the firsttransistor 101 is connected to the signal line 109, and the drainelectrode 113 of the first transistor 101 is connected to the gateelectrode 107′ of the second transistor 102. In addition, the drainelectrode 102′ of the second transistor 102 is connected to the firstcurrent supply line 110, and the capacitance upper electrode 108 isconnected to the first current supply line 110.

Next, the second interlayer insulation layer 118, the first electrode114 and the third interlayer insulation layer 119 are formed in the samemanner as in the first embodiment. On the upper side of this, a holetransport layer 121, a light-emitting layer 122, an electron transportlayer 123, an electron injection layer 124, and a second electrode 125are formed by the same methods as in the first embodiment.

The second electrode 125 is connected to the second current supply line501′ at the feeding points 503′, 504′.

Thereafter, the substrate provided with the driving devices and theorganic light-emitting devices and a sealing substrate 309 are adheredto each other in the same manner as in the third embodiment.

In the organic light-emitting display system according to thisembodiment, the second electrode 125 and the second current supply lines501′, 502′ are connected to each other in the display region of eachpixel, so that variations in the wiring resistance of the secondelectrode 125 are reduced. In particular, since the second currentsupply lines 501′, 502′ are formed in a mesh form, the wiring resistanceof the second current supply lines is further lowered, and, as a result,variations in the brightness of the panel surface can be reduced.

The embodiment of the invention adopts a mesh configuration in which thesecond current supply lines are disposed in the directions of the signallines (the longitudinal direction) and the scanning lines (lateraldirection) for each sub-pixel. To reduce the variations in the wiringresistance, the second current supply lines are not necessarily disposedin the longitudinal and lateral directions for every sub-pixel. Forexample, the second current supply lines are disposed in thelongitudinal direction for each sub-pixel as with this embodiment, whilethe second current supply lines are disposed in the lateral directiononly for sub-pixels located at the central portion of the displayregion. This configuration reduces the variations in the wiringresistance as compared with a configuration in which the second currentsupply lines are disposed only in the longitudinal direction. Inaddition, as compared with the fifth embodiment, although the variationin the wiring resistance is increased, the number of the contact holesthat connect the second current supply lines disposed in thelongitudinal direction with the second current supply lines disposed inthe lateral direction is decreased, which improves a process percentdefective.

The second current supply lines disposed in the lateral direction may beformed every two, three or four sub-pixels. In addition, even if thedispositions of the second current supply lines formed in the lateraland longitudinal directions are exchanged for each other, the sameeffects can be produced.

[Embodiment 6]

A full-color organic light-emitting display device according to a sixthembodiment of the present invention will be described with reference toFIGS. 12 and 13. This display device has feeding points to secondcurrent supply lines provided at a plurality of sub-pixels constitutinga pixel. FIG. 12 is a plan view of a pixel of the organic light-emittingdisplay system according to this embodiment, and FIG. 13 is a sectionalview taken along line A-A′ of the pixel region shown in FIG. 12.

In this embodiment, to form feeding points to the second current supplylines 111, 111′, 111″ for each sub-pixel constituting each pixel of eachcolor picture, the second current supply lines 111, 111′, 111″ areformed respectively in display regions of red, green and blue pixels,and a second electrode 125 is connected to the second current supplylines 111, 111′, 111″ through contact holes 114, 114′, 114″ in thedisplay regions of each sub-pixel, the other constitutions beingsubstantially the same as in the second embodiment.

More particularly, there are formed on a glass substrate 116, a greenpixel first transistor 204, a green capacitance 205, a green secondtransistor 206, a red pixel first transistor 207, a red capacitance 208,a red second transistor 209, a blue pixel first transistor 210, a bluecapacitance 211, a blue second transistor 212, signal lines 109, 109′,109″, scanning lines 106, 106′, first current supply lines 110, 110′,110″, second current supply lines 111, 111′, 111″, a first inter-layerinsulation film 118 and a second inter-layer insulation film 119, whichare formed by the same methods as in the second embodiment.

Next, contact holes 114, 114′, 114″ are formed in the first interlayerinsulation film 118 and the second interlayer insulation film 119 atupper portions of the second current supply lines 111, 111′, 111″,respectively, and each of the contact holes 114, 114′, 114″ is made tobe a feeding point.

Subsequently, first electrodes 201, 202, 203 for green, red and bluepixels are formed under the same formation conditions as in the secondembodiment. The shapes of the first electrodes 201, 202, 203 are shownin FIG. 12.

Next, a third inter-layer insulation film 120 is formed by the samemethod as in the second embodiment.

Subsequently, hole transport layers 601, 603, 605 are respectivelyformed on the first electrodes 201, 202, 203 of the sub-pixels under thesame formation conditions as in the second embodiment. The holetransport layers 601, 603, 605 are formed in such a pattern as not tocover the contact holes 114, 114′, 114″, respectively, the contact holesserving as feeding points.

Next, light-emitting layers 213, 214, 215 are formed on the holetransport layers 601, 603, 605, respectively, by the same method as inthe second embodiment.

Subsequently, electron transport layers 602, 604, 605 are formed on thelight-emitting layers 213, 214, 215, respectively, by the same method asin the second embodiment.

Next, an Mg—Ag alloy film serving as an electron injection layer 124 isformed on the electron transport layers 602, 604, 605 under the sameformation conditions as in the second embodiment. An IZO film serving asa second electrode 125 is formed on the electron injection layer 124under the same formation conditions as in the second embodiment.

The second electrode 125 is connected to the second current supply lines111, 111′, 111″ through the contact holes 114, 114′, 114″, respectively,which are formed in the first inter-layer insulation film 118 and thesecond inter-layer insulation film 119. That is, the second electrode125 of each sub-pixel is connected to the second current supply lines111, 111′, 111″ in the display region of each sub-pixel, with thecontact holes 114, 114′, 114″ serving as feeding points.

Subsequently, an SiNx film of 50 nm in thickness is formed by a thermalCVD method. This film functions as a protective layer 126.

According to this embodiment, the second electrode 125 is connected tothe second current supply lines 111, 111′, 111″ in the display regionsof the sub-pixels of each pixel, so that variations in wiring resistancedue to the resistance of the second electrode 125 of each pixel can besuppressed, and variations in the brightness of the panel can bereduced.

[Embodiment 7]

A full-color organic light-emitting display system according to aseventh embodiment of the present invention will be described withreference to FIGS. 14 and 15. This display device has a configuration inwhich a new metallic layer and an interlayer insulation film areprovided at a driving layer comprising an organic layer, and a secondcurrent supply line is formed of the new metallic layer. FIG. 14 is aplan view of a pixel of the organic light-emitting display systemaccording to this embodiment, and FIG. 15 is a sectional view takenalong line A-A′ of the pixel region shown in FIG. 14.

In this embodiment, a metallic layer and an interlayer insulation filmare provided between a wiring layer comprising signal lines 109, 109′,109″ and first current supply lines 110, 110′, 110″ and a driving layercomprising an organic layer to form second current supply lines 111,111′, 111″, the other constitutions being the same as in the sixthembodiment.

More particularly, up to the step of forming a second interlayerinsulation film 119 on a glass substrate 116, the processing is the sameas in the sixth embodiment, except that the second current supply lines111, 111′, 111″ are formed to be a layer other than the wiring layercomprising the signal lines 109, 109′, 109″ and the first current supplylines 110, 110′, 110″.

Next, the second current supply lines 111, 111′, 111″ are formed on thesecond inter-layer insulation film 119 by the same method as used in thesixth embodiment.

Subsequently, a polyimide coat film serving as a fourth interlayerinsulation film 701 is formed on the second current supply lines 111,111′, 111″. The polyimide film is formed by use of a self (thin film)non-photosensitive polyimide (code No. PIX-1400), a product of HitachiChemical DuPont MicroSystems. The film is formed by a spin coatingmethod, with two-fold dilution using NMP as a solvent. First, thesolution is diffused on the entire surface of the substrate at 500 rpmfor 10 sec, then a polyimide film is really formed under the conditionsof 6000 rpm and 30 sec. Thereafter, the substrate is placed on a hotplate in the atmosphere, and baking is conducted by sequentiallychanging the baking temperature (baking time) in the sequence of 110° C.(3 min), 190° C. (3 min), 270° C. (3 min) and 350° C. (5 min). Thethickness of the polyimide film is 500 nm. The fourth interlayerinsulation film 701 is also provided with contact holes 114, 114′, 114″as feeding points.

Subsequently, first electrodes 205, 208, 211 for green, red and bluepixels, a third interlayer insulation film 120, hole transport layers601, 603, 605, light-emitting layers 213, 214, 215, electron transportlayers 602, 604, 606, an electron injection layer 124, a secondelectrode 125, and a protective layer 126 are formed on the fourthinterlayer insulation film 701 by the same methods as in the sixthembodiment.

According to this embodiment, the second electrode 125 and the secondcurrent supply lines 111, 111′, 111″ are connected to each other in thedisplay regions of each sub-pixel, with the contact holes 114, 114′,114″ serving as feeding points, so that variations in wiring resistancedue to the second electrode 125 can be suppressed, and variations in thebrightness of the panel can be reduced.

Besides, according to this embodiment, the second current supply lines111, 111′, 111″ are formed in a layer different from the layer of thefirst current supply lines 110, 110′, 110″, so that it is possible toenlarge the width of the wiring, and a lowering in the resistance of thesecond current supply lines 111, 111′, 111″ can be contrived.

[Embodiment 8]

A full-color organic light-emitting display device according to aneighth embodiment of the present invention will be described withreference to FIGS. 16 and 17. This display device has a configuration inwhich a metallic layer and an interlayer insulation film are formed at adriving layer comprising an organic layer and a second current supplyline is formed of the metallic layer. FIG. 16 is a plan view of a pixelof the organic light-emitting display device according to thisembodiment, and FIG. 17 is a sectional view taken along line A-A′ of thepixel region shown in FIG. 16.

In this embodiment, a metallic layer and an interlayer insulation filmare formed between a wiring layer comprising signal lines 109, 109′,109″ and first current supply lines 110, 110′, 110″ and a driving layercomprising an organic layer, and a second current supply line is formedof the metallic layer, in the same manner as in the seventh embodimentexcept that the second current supply line 801 is formed in parallel tothe scanning lines 106, 106′ in this embodiment, as contrasted to theseventh embodiment in which the second current supply lines 111, 111′,111″ are formed in parallel to the signal lines 109, 109′, 109″, andthat the second current supply line 801 is provided with contact holes114, 114′, 114″.

More particularly, up to the step of forming a second inter-layerinsulation film 119 on a glass substrate 116, the processing is the sameas in the seventh embodiment.

Next, the second current supply line 801 is formed on the secondinterlayer insulation film 119. The second current supply line 801 isformed in parallel to the scanning lines 106, 106′ by the same method asin the seventh embodiment. The subsequent steps are the same as in theseventh embodiment.

According to this embodiment, the second electrode 125 is connected tothe second current supply line 801 on a sub-pixel basis, with thecontact holes 114, 114′, 114″ serving as feeding points, so thatvariations in wiring resistance due to the second electrode 125 can besuppressed, and variations in the brightness of the panel can bereduced.

In addition, according to this embodiment, the second current supplyline 801 is formed in a layer different from the layer of the firstcurrent supply lines 110, 110′, 110″, so that the wiring width of thesecond current supply line 801 can be enlarged, and a lowering in theresistance of the second current line 801 can be achieved.

[Embodiment 9]

A full-color organic light-emitting display device according to a ninthembodiment of the present invention will be described with reference toFIGS. 18 and 19. This display device has a configuration in which secondcurrent supply lines for exclusive use for individual sub-pixels areconnected to individual color sub-pixels. FIG. 18 is a plan view of apixel of the organic light-emitting display system according to thisembodiment, and FIG. 19 is a sectional view taken along line A-A′ of thepixel region shown in FIG. 18.

In this embodiment, second current supply lines 111, 111′, 111″ parallelto signal lines are formed for each of sub-pixel of each pixel, andsecond electrodes 901, 902, 903, which are respectively connected to thesecond current supply lines 111, 111′, 111″ of the individualsub-pixels, are connected in the display regions of the individualsub-pixels, with contact holes 114, 114′, 114″ serving as feedingpoints. In addition, green pixels, red pixels and blue pixels are formedin a stripe pattern with each kind of these pixels arranged in a row,and a sealing substrate 309, which is provided for the purpose ofpreventing water, oxygen and the like gases in the atmosphere frompenetrating into the second electrodes, an organic layer under thesecond electrodes or the interface between the second electrodes and theorganic layer is provided on the upper side of the second electrodes901, 902, 903. Other constitutions are the same as in the sixthembodiment.

More particularly, the steps from the step of forming the firsttransistors 204, 207, 210 on a glass substrate 116 up to the step offorming the electron injection layers 307, 307′, 307″ are the same as inthe sixth embodiment, whereby the green pixels, red pixels and bluepixels are formed in a stripe pattern with each kind of the pixelsarranged in a row.

The second electrodes 901, 902, 903 in a stripe pattern are formed onthe electron injection layers 307, 307′, 307″ by use of a metal maskunder the same conditions as in the sixth embodiment.

Although a metal mask is used for patterning in forming the secondelectrodes 901, 902, 903, this is not limitative. For example, edgeportions of a third interlayer insulation film 120 may be formed in areverse-tapered shape, and the second electrodes 901, 902, 903 may beformed in a cut-apart state so as to be in a stripe pattern, withoutusing a mask.

Subsequently, sealing is conducted, by use of a sealing substrate 309,in the same manner as in the third embodiment.

According to this embodiment, the second electrodes 901, 902, 903 arerespectively connected to the second current supply lines 111, 111′,111″ in the display regions of the individual sub-pixels of each pixel,with the contact holes 114, 114′, 114″ serving as feeding points, sothat variations in wiring resistance due to the second electrodes 901,902, 903 can be suppressed, and variations in the brightness of thepanel can be reduced.

In addition, according to this embodiment, the green pixel, red pixeland blue pixel constituting the sub-pixels of each pixel are connectedthrough the second current supply lines 111, 111′, 111″ for exclusiveuse, with the contact holes 114, 114′, 114″ serving as feeding points,so that the voltage or current applied to each sub-pixel can becontrolled independently.

According to the present invention, at least the electrode on one sideof one organic light-emitting device belonging to each pixel isconnected to the current supply line in the display region of eachpixel, so that dispersion of luminance due to the resistance of wiringfor connecting the electrodes of the organic light-emitting devices anda power source can be reduced, and dispersion of luminance in thedisplay region can be suppressed.

[Embodiment 10]

Next, a description will be made of a tenth embodiment, in which firstcurrent supply lines and second current supply lines are disposed in amesh form, with reference to FIGS. 21 and 22. FIG. 21 is a plan view ofa pixel of an organic light-emitting display system in this embodiment.FIG. 22 is a sectional view of a pixel region taken along line A-A′ ofFIG. 21. This display system comprises first current supply lines 110′,110 and second current supply lines 501′, 501 that are formed in alongitudinal direction in a wiring layer in which signal lines 109, 109′are also formed; and a first current supply line 603 and a secondcurrent supply line 604, that are formed in a lateral direction in awiring layer in which a gate line 503′ is also formed. The firstlongitudinal current supply lines 110′ and 110 are connected to thefirst lateral current supply line 603 at their respective intersectionsthrough contact holes 601′ and 601, respectively. The secondlongitudinal current supply lines 501′ and 501 are connected to thesecond lateral current supply line 604 at their respective intersectionsthrough contact holes 602′ and 602, respectively. Thus, the first andsecond current supply lines are each formed in a mesh manner. Inaddition, second electrodes are connected to the second current supplylines 501′ and 501 through contact holes 606′ and 606, respectively,serving as feeding points. Other portions are configured similarly tothose of the fifth embodiment.

With this configuration, since the resistance of the first and secondcurrent supply lines can be reduced, variations in the wiring resistancecan be suppressed, and, as a result, variations in the brightness of thepanel surface can be lowered. In particular, a drop in the voltage ofthe first current supply line varies the reference voltages of secondtransistors 102, 102′ that determine the display brightness of a pixel,so that a small variation in voltage causes a large variation incurrent. To suppress the variation in drops in the voltage of the firstcurrent supply lines is therefore effective at suppressing thevariations in the brightness of the panel surface.

For example, a variation in voltage of 0.5 V in the first current supplylines approximately corresponds to a variation in gate bias voltage of atransistor. Accordingly, an S value of 0.5 V/dec of the transistorcauses a variation in the current by as much as ten times. On the otherhand, a variation in voltage of 0.5 V in the second current supplylines, which corresponds to a variation in EL drive voltage, affects thebrightness. Therefore, when it is assumed that VDS=8 V, avoltage-current characteristic is an exponential function, and an indexI is Ioe^(0.8V), a current ratio is 1.5 times and the brightness variesby about 1.5 times. Thus, even small drops in the voltage of 1 V or lessin the first current supply line and the second current supply lineresult in a large variation in the brightness in either case. Inparticular, the variation in the voltage of the first current supplyline results in the greater variations in the brightness. The reductionin the variations of the resistance presented by this embodimentproduces the effect of reducing the variations in the brightness.

In addition, the thus configured mesh-like wiring can reduce thevariations in voltage between laterally adjacent pixels or sub-pixels,so that smear can be reduced.

The smear occurs in the following manner. As described in the proceedingembodiments, in the case where the first current supply lines aredisposed in parallel with the signal lines in a stripe pattern, thecurrent of the first current supply line varies in response to theaverage brightness of a longitudinally disposed sub-pixel connected tothe corresponding first current supply line, and, consequently, a dropin voltage freely varies on a longitudinal line basis. Accordingly, evenif patterns with the same brightness are to be displayed at thegenerally central portion of the panel, a variation in brightness of oneof the patterns positioned at the central portion occurs in response tothe corresponding displayed pattern that is positioned at the peripheralportion of the panel in each of the longitudinal directions.

Since the lateral current supply lines are connected to the longitudinalcurrent supply lines in this embodiment, the variations in voltage canbe reduced in both the longitudinal and lateral directions, therebypreventing the smear from occurring.

[Embodiment 11]

An eleventh embodiment will be described with reference to FIGS. 23 and24. In this embodiment, an aluminum wiring layer with low resistance andan insulating interlayer are additionally provided in a grid form andare used as a first current supply line layer. FIG. 23 is a plan view,and FIG. 24 shows a sectional configuration. The additional aluminumwiring layer 605 and interlayer insulation film 610 are formed by aprocess similar to that of the third embodiment. A second interlayerfilm 119 is formed and second current wiring contacts 602, 602′ andfirst current wiring contacts 614, 614′ are formed. Thereafter, thealuminum wiring layer 605 and the additional interlayer insulating film610 are formed and a contact hole 608 is provided. Then, an EL device isformed and a second electrode 125 is formed as an uppermost layer.

Each aluminum wiring layer 605 is provided with an opening 11 for eachpixel so as to allow light from the substrate surface to passtherethrough. A second electrode 124 formed in the uppermost layer isconnected to second current supply lines 501, 501′ through therespective contacts 602, 602′ provided below the respective contactopenings 612, 612′. On the other hand, the aluminum wiring layer 605 asa first current supply line is connected to second transistors 102, 102′through the first current supply line contacts 614, 614′, respectively.

With this configuration, the area of the first current supply linehaving a large effect on variations in brightness can be remarkablyincreased to reduce a drop in voltage, so that the variations inbrightness can be reduced. In addition, this configuration produces alarge effect of reducing smear. This is because the aluminum wiringlayers having low resistance are used in a grid form. In particular, aneffect of improving the image quality due to the grid-like wiring in anorganic EL panel, which is a current drive device, is remarkably largerthan that in a liquid crystal display. Also, a liquid crystal displaysystem is provided with wiring which supplies the same potential to eachpixel in common. However, since the liquid crystal display isvoltage-driven and the device is driven by an electric capacitive loadin its operation principle, it is necessary to improve the image qualityof the display by matching the selected time for a pixel with the timeconstant of a transient response of the wiring. For the current drivedevice, such as an organic EL, since an electric current flows steadilyduring the period of display after the period of scanning, it isnecessary to suppress the variations in brightness of the display bysuppressing a drop in the voltage due to the wiring resistance itself.Thus, the current drive device is significantly different from theliquid crystal display in the manner of exhibiting the wiring resistanceeffect. Since the current wiring layer is made of aluminum having a lowresistivity and is formed in a grid form so as to be low-resistant, thisembodiment has the advantages of eliminating variations in brightnessand smear.

[Twelfth embodiment]

A twelfth embodiment will be described with reference to FIGS. 25 and26. In the present embodiment, first and second longitudinal currentsupply lines are each disposed in parallel with a signal line, and firstand second lateral current supply lines are each disposed in parallelwith a scanning line. The first and second longitudinal current supplylines are connected to the first and second lateral current supply linesin a grid form. In particular, for the longitudinal lines disposedparallel to the signal line, an aluminum wiring layer having a lowresistance and an interlayer insulation film, which are additionallyprovided as with the eleventh embodiment, are used. This configurationenlarges the respective widths of the first and second longitudinallines so as to provide the effects of reducing the resistance thereofand reducing smear.

The manufacturing process of this embodiment is similar to that of theeleventh embodiment. That is, first current supply lines 110, 110′ andsecond current supply lines 501, 501′ are formed of aluminum wiring andare disposed in parallel with signal lines 109, 109′. On the other hand,first and second lateral current supply lines 603, 604 are disposed inparallel with a scanning line and are formed in a scanning wiring layer.The first longitudinal current supply lines 110 and 110′ are connectedto the first lateral current supply line 603 through contact holes 601and 601′, respectively, while the second longitudinal current supplylines 501 and 501′ are connected to the second lateral current supplylines 604 through contact holes 602 and 602′, respectively.Incidentally, second electrodes 125 are connected to the second currentsupply lines 501 and 501′ through contact holes 606 and 606′,respectively, serving as feeding points. In addition, the first currentsupply line 110 is connected to a second transistor 102 through aconnection pattern 609 and a contact hole 607; while, the first currentsupply line 110′ is connected to a second transistor 102′ through aconnection pattern 609′ and a contact hole 607′.

While the invention has been described with reference to preferredembodiments, it is to be understood that the words which have been usedare words of description rather than limitation and that changes withinthe purview of the appended claims may be made without departing fromthe true scope and spirit of the invention in its broader aspects.

1. An organic light-emitting display device comprising: a plurality ofpixels each of which is a minimum unit of a picture; and a plurality oforganic light-emitting devices as each said pixel; wherein at least anelectrode on one side of one organic light-emitting device belonging toeach said pixel, of a pair of electrodes disposed on the opposite sidesof an organic layer of said plurality of organic light-emitting devices,is connected to a current supply line in a display region of each saidpixel, and wherein a driving layer comprising a driving device to drivesaid organic layer is stacked on a substrate, a wiring layer comprisingsignal lines and scanning lines connected to said driving device isstacked, said organic layer of said plurality of organic light-emittingdevices is stacked on said wiring layer on a pixel basis together withthe pair of electrodes disposed on the opposite sides of said organiclayer, and said current supply line is disposed in said wiring layer andconnected to said electrode on one side through an interlayer insulationfilm.
 2. An organic light-emitting display device comprising: aplurality of pixels each of which is a minimum unit of a picture; and aplurality of organic light-emitting devices as each said pixel; whereinan electrode on one side, of a pair of electrodes disposed on theopposite side of an organic layer of said plurality of organiclight-emitting devices, is connected to a current supply line in adisplay region of each said pixel, and wherein a driving layercomprising a driving device to drive said organic layer is stacked on asubstrate, a wiring layer comprising signal lines and scanning linesconnected to said driving device is stacked, said organic layer of saidplurality of organic light-emitting devices is stacked on said wiringlayer on a pixel basis together with the pair of electrodes disposed onthe opposite sides of said organic layer, and said current supply lineis disposed in said wiring layer and connected to said electrode on oneside through an interlayer insulation film.
 3. An organic light-emittingdisplay device comprising: a plurality of pixels each of which is aminimum unit of a color picture; and a plurality of organiclight-emitting devices different in emitted light color as each saidpixel; wherein at least an electrode on one side of one organiclight-emitting device belonging to each said pixel, of a pair ofelectrodes disposed on the opposite sides of an organic layer of saidplurality of organic light-emitting devices, is connected to a currentsupply line in a display region of each said pixel, and wherein adriving layer comprising a driving device to drive said organic layer isstacked on a substrate, a wiring layer comprising signal lines andscanning lines connected to said driving device is stacked, said organiclayer of said plurality of organic light-emitting devices is stacked onsaid wiring layer on a pixel basis together with the pair of electrodesdisposed on the opposite sides of said organic layer, and said currentsupply line is disposed in said wiring layer and connected to saidelectrode on one side through an interlayer insulation film.
 4. Anorganic light-emitting display device comprising: a plurality of pixelseach of which is a minimum unit of a color picture, and a plurality oforganic light-emitting devices different in emitted light color as eachsaid pixel; wherein an electrode on one side, of a pair of electrodesdisposed on the opposite sides of an organic layer of said plurality oforganic light-emitting devices, is connected to a current supply line ina display region of each said pixel, and wherein a driving layercomprising a driving device to drive said organic layer is stacked on asubstrate, a wiring layer comprising signal lines and scanning linesconnected to said driving device is stacked, said organic layer of saidplurality of organic light-emitting devices is stacked on said wiringlayer on a pixel basis together with the pair of electrodes disposed onthe opposite sides of said organic layer, and said current supply lineis disposed in said wiring layer and connected to said electrode on oneside through an interlayer insulation film.
 5. An organic light-emittingdisplay device comprising: a plurality of pixels each of which is aminimum unit of a color picture; and a plurality of organiclight-emitting devices different in emitted light color as each saidpixel; wherein an electrode on one side of said organic light-emittingdevice of a specified emitted color light of each said pixel, of a pairof electrodes disposed on the opposite sides of an organic layer of saidplurality of organic light-emitting devices, is connected to a currentsupply line in a display region of each said pixel, and, wherein adriving layer comprising a driving device to drive said organic layer isstacked on a substrate, a wiring layer comprising signal lines andscanning lines connected to said driving device is stacked, said organiclayer of said plurality of organic light-emitting devices is stacked onsaid wiring layer on a pixel basis together with the pair of electrodesdisposed on the opposite sides of said organic layer, and said currentsupply line is disposed in said wiring layer and connected to saidelectrode on one side through an interlayer insulation film.
 6. Anorganic light-emitting display device comprising: a plurality of pixelseach of which is a minimum unit of a picture; a plurality of organiclight-emitting devices as each said pixel; and at least one currentsupply line disposed in a display region including each said pixel;wherein at least an electrode on one side of one organic light-emittingdevice belonging to each said pixel, of a pair of electrodes disposed onthe opposite sides of an organic layer of said plurality of organiclight-emitting devices, is connected to said current supply line in adisplay region of each said pixel, and, wherein a driving layercomprising a driving device to drive said organic layer is stacked on asubstrate, a wiring layer comprising signal lines and scanning linesconnected to said driving device is stacked, said organic layer of saidplurality of organic light-emitting devices is stacked on said wiringlayer on a pixel basis together with the pair of electrodes disposed onthe opposite sides of said organic layer, and said current supply lineis disposed in said wiring layer and connected to said electrode on oneside through an interlayer insulation film.
 7. An organic light-emittingdisplay device as set forth in claim 1, wherein said current supply lineis disposed in a layer between said wiring layer and said organic layer.8. An organic light-emitting display device as set forth in claim 1,wherein an electrode on one side of a pair of electrodes disposed on theopposite side of said organic layer of said plurality of organiclight-emitting devices is formed at an upper portion of said organiclayer on a substrate as a second electrode, against a first electrodeformed at a lower portion of said organic layer on said substrate, andsaid current supply line is connected to an upper portion of said secondelectrode.
 9. An organic light-emitting display system as set forth inclaim 1, wherein an electrode on one side of a pair of electrodesdisposed on the opposite sides of said organic layer of said pluralityof organic light-emitting devices is formed at an upper portion of saidorganic layer on said substrate as second electrodes, against a firstelectrode formed at a lower portion of said organic layer on saidsubstrate, and said current supply line is connected to an upper portionof said second electrode.
 10. An organic light-emitting display deviceas set forth in claim 1, wherein at least two said current supply linesare connected to each other.
 11. An organic light-emitting displaydevice as set forth in claim 1, wherein said current supply line isdivided into a plurality of current supply lines in correspondence witheach said organic light-emitting device of each said pixel, and saidplurality of current supply lines thus divided are each connected toeach said organic light-emitting device of each said pixel as anexclusive-use current supply line.
 12. An organic light-emitting displaydevice as set forth in claim 1, wherein said current supply line isformed along each space between said pixels.
 13. An organiclight-emitting display device as set forth in claim 1, wherein saidcurrent supply line is formed to overlap each said pixel.
 14. An organiclight-emitting display device as set forth in claim 5, wherein saidorganic light-emitting device of said specified emitted light color hasa higher efficiency or a longer life as compared with said organiclight-emitting devices of other emitted light colors.
 15. An organiclight-emitting display device as set forth in claim 1, wherein anelectrode on one side of a pair of electrodes disposed on the oppositesides of said organic layer of said plurality of organic light-emittingdevices is formed at an upper portion of said organic layer on asubstrate as a second electrode, against a first electrode formed at alower portion of said organic layer on said substrate, said firstelectrode is connected to a plus terminal of a power source as an anode,and said second electrode is connected to a minus terminal of said powersource as a cathode.
 16. An organic light-emitting display device as setforth in claim 15, wherein said second electrode is formed of atransparent material which transmits light there through.